An SEIR Model for Assessment of Current COVID-19 Pandemic Situation in the UK

Peiliang SUN; Kang Li

By performing the aforementioned modeling procedures, estimates of the number of actual infected people with different infection fatality ratio κ and different severe case ratio λ H are plotted in Figure 6 . The figure indicates that although the actual IFR κ cannot be calculated accurately, based on our modeling results shown in Figure 6 , the total number of infected cases could have been greater than 0.61 million by 1 April 2020. If the IFR κ was lower than 2%, the total case number could be even greater than 1 million. Several reports indicate that IFR is below 1% [2] , but based on our model, the lower IFR κ implies lower severe case ratio λ H and larger infection number. Hence, the total number of infections would exceed 2 million if IFR κ is below 1%. However, according to the UK demographic data, about 5% infected individuals may need hospital treatment, therefore a higher IFR (κ > 2%) is more likely to be true in the early stage of this virus outbreak.